This invention relates to a system for providing releasable engagement between two structures. More particularly, this invention relates to a system adapted to maintain a predetermined gap between two engaged structures.
Latching systems are often used for latching structures such as a hinged door to a fixed frame. In certain applications, such latching systems require a turning motion such as would be needed with a conventional latch and pawl system.
In some instances, latching mechanisms may be required for large doors such as sheet metal or molded plastic doors. Such doors can be several feet in height, and twisting and bowing of the doors can become a problem. Moreover, such twisting and bowing of the doors can result in the formation of an inconsistent gap between the door and the frame, which may not be aesthetically appealing. Also, in applications such as computer system housings where the housing door provides an electromagnetic interference (EMI) seal, such gaps can result in leakage and system failure.
In order to resolve the problems associated with variable gaps, it has been proposed to use retention points at several locations along the latched edge of the door. Typically, these retention points are at the top, bottom, and center portions of the door. It has been proposed to use tie rods or cables that span the distance between these spaced retention points in order to ensure that the latches all disengage appropriately when the door is opened.
It has been recognized, however, that such tie rod or cable systems take up space along the edge of the door. The use of such tie rod or cable systems therefore limits the availability of space for other structural features including, for example, stiffening features of the door.
Accordingly, there remains a need for a cost-effective system for latching a hinged door to a fixed frame. Preferably, the latching system should be capable of operation without requiring a turning motion, such as that of a latch and pawl system Furthermore, the latching system should preferably be capable of providing a secure fit with a consistent gap maintained along the interface between a door and a frame. Also, where multiple latches are desired, the latching system should preferably provide latch engagement for each latch that is independent of the others, thereby avoiding the requirement of mechanical linkages between the latches that reduce the available space in the door or frame for other mechanical or cosmetic features, and thereby reducing the cost of such linkages as well as the assembly time associated therewith.
This invention provides a system for providing releasable engagement between two structures such as the door and frame of a computer housing, for example. The system includes a stud extending outwardly from one of the structures along an axis. The outer surface of the stud can be grooved about its circumference to define a surface oriented at an angle to the axis. The system also includes a resilient member positioned adjacent a surface of the other one of the structures. The resilient member has a substantially torroidal configuration, an outer surface contacting the surface of the housing structure to prevent movement of the outer surface radially outwardly, and an inner surface that is movable radially outwardly.
The torroidal configuration of the resilient member defines an opening that is smaller than the stud. The opening of the resilient member is configured to expand radially outwardly to permit passage of the stud Also, the resilient member is configured to engage the surface of the stud for releasable engagement of the stud, thereby providing releasable engagement between the structures.
According to a preferred feature of the invention, the system can also include means positioned adjacent to the resilient member for urging the stud outwardly from the resilient member. According to one preferred embodiment, the urging means includes a button positioned for movement along the axis of the stud to urge the stud out from the resilient member along the stud""s axis. According to another preferred embodiment, the urging means includes a lever positioned to urge the stud out from the resilient member along the axis of the stud.
When used with larger structures, the system according to this invention can include a plurality of studs and resilient members. The system according to this invention makes it possible to maintain a predetermined gap between such structures.